Means and process for the amplifi



. y 1938- Y J. .J. DALEY Re. 20,735

MEANS AND PROCESS FOR THE AMPLIFICATION OF RADlANT ENERGY Original FiledOct. 24, 1927 M c. Qlip Reissued May 24, 1938 UNITED STATES PATENTOFFICE,

MEANS AND PROCESS FOR THE AlVlIPLIFI- GATION OF RADIANT ENERGY Joseph J.Daley,

Boston,

Mass., assignor, by

mesne assignments, to Research Products Ourporation, Boston, Mass., acorporation of Massachusetts 15 Claims.

This invention relates to a novel method of amplification of radiantenergy and the avoidance of such currents as produce undesiredoscillation in the amplifier circuit. Heretofore, the 'oscillationsproduced by these currents were largely the limiting factor in radiofrequency amplification, and it was found necessary to suppress them byresorting to external means to produce other currents in opposition, orto introduce high resistance into the circuit. Either method wasundesirable since. the introduction of resistance materially reduced theeiliciency of the circuit, making it less sensitive and less selective;while the method depending upon the production of an opposing currentnot only reduced the overall efficiency of the amplifier, but was'initself effective only over a very limited range of frequency.

Heretofore all systems of reception and ampliflcation of radiant energywere built around the conception that these disturbing currents andtheir consequent oscillations were inevitable. Certain systems sought toforce these oscillations further to produce a form of amplification inconnection with the detector tube but this gave rise to very seriousdistortion and undesirable noises. When true amplification at highfrequencies was attempted these oscillations, as stated above, becamethe limiting factor and had to be damped and suppressed before anyappreciable degree of amplification could be obtained. It has been foundthat when these undesired oscillatory currents have been suppressed to adegree that permits of reasonable amplification, the desired and usefuloscillatory currents in the circuit have also been suppressed to a veryconsiderable degree, thus reducing the efficiency of the entire circuit.

I have found that apart from the condition of self-sustained and/orforced oscillations and the condition of neutralized and/or dampedoscillations there exists a third condition where there is no flow ofcurrents which will produce undesired oscillations and therefore nore.genera tion. In my invention I have brought about this condition oftrue non-regeneration, neverbefore realized, by a novel arrangement andselection of values of inductances and capacities I, 2, M between I and2, 9, 3, Ill and 4 which in themselves constitute the amplifier circuit.This condition of true non-regeneration is obtained by selection ofvalues which will produce a zero difference of potential in respect toall regenerative currents in any phase between the elements, such asgrid and plate, of the electronic device at any desired frequency. Theelectrical relation of the various parts of the circuit is such thatthis condition of true non-regeneration is automatically maintained forany desired frequency; and since no regenerative currents in any phasecan now exist, all necessity for their suppression by any means externalto the necessary circuit elements has been eliminated. This novelarrangement of inductances and capacities more specifically describedbelow produces a higher degree'of amplification per stage than has beenobtainable by any other system and eliminates entirely the distortionsand noises set up when regenerative currents in any phase are present.

I have also found that distortion and unstable operation in an amplifiermay be present even when the undesired oscillatory currents are notpresent. This condition is brought about by the flow of currents,desirable in themselves, in a path where they do not belong. In otherwords, to obtain a high degree of efficiency in amplification withoutdistortion, the circuit must contain only the useful and desirablecurrents and their flow must be restricted to their proper and usefulpaths. The means by which I accomplish this object are described indetail below.

Thus this invention makes possible optimum amplification at any desiredfrequency and equal amplification at all frequencies without disturbingcurrents.

Since the energy transfer due to electromagnetic coupling increases withan increase of frequency, and since the magnetic coupling remainsconstant at its optimum value, the point is quickly reached at which thetube and circuit will go into violent oscillation, thereby distortingall reception and/or amplification. In my invention, however, the energytransfer takes place not only by means of electromagnetic coupling, butalso by means of electrostatic coupling simultaneously. The value ofenergy transfer through static coupling is a function of frequency, andif the value of the static coupling were constant, the combination ofmagnetic and static coupling must still vary with frequency inapproximately a straight line ratio. Since the energy transfer throughthe static coupling varies coincidentally with changes in receivedfrequency but in the inverse ratio, the combination of magnetic andstatic coupling and the associated inductances and capacities could be.made to produce, by a proper selection of values, the maximum transferof energy without permitting at any time the existence of disturbingcurrents which produce undesired oscillations in the tube.

In this invention, the direct means used to create static coupling is acapacity connecting the primary and secondary windings of the radiofrequency transformer. This capacity, however, is also in series withthe variable condenser, and therefore the real value of the effectivetuning electrostatic leg of this system must be represent ed by thevalues of the two capacities in series, which would be mathematicallyspeaking the value of one over the sum of their reciprocals. In otherwords,

In this electrostatic leg, the variable condenser is to the couplingcondenser in or about the ratio of 1 to 20. Therefore, as the system istuned to a higher frequency, the value of the variable condenser isreduced, thereby reducing the entire value of the static coeflicient ofcoupling which, combined with other factors, compensates for theincrease in value of magnetic coupling due to increased frequency.Conversely, as frequency decreases, the increase in value of thevariable condenser increases the static coeflicient of coupling andthereby, combined with other factors, compensates for the decreasedvalue of the magnetic coefficient of coupling for the lower frequency.

The determination of the values of the two capacities must be mademathematically by following the formula where C is the variablecondenser, and C is a capacity of fixed value. For any desired band offrequencies, the value of 0 must be such as to produce the proper tuningwith its associated inductance and capacity.

When the proper values have been obtained, the act of tuning willautomatically maintain the proper balance between the electromagneticand electrostatic legs, thus maintaining the maximum energy transfer atall frequencies, and other elements properly considered preventing theproduction of such currents as would produce undesired oscillations.

In addition, all other undesired currents are excluded from thecircuits, and all undesired transfers of energy from one part of thecircuit to another are prevented by means of choke coils and condensers,etc. as shown hereinafter.

The inductances used in the magnetic leg of this amplifier circuit takethe form of transformers. I have found as a result of a long series ofexperiments that the introduction of a direct current into the primaryof such a. transformer is extremely detrimental. The radio currentsimpressed upon the primary of such a transformer are necessarily of avery low intensity and are modulated for example by voice frequencies,music or other modulating frequencies. It is desired that the currentinduced in the secondary winding of the transformer retain without anychange the modulation characteristics of the original current althoughthere may have been a certain definite increase in voltage. If anydirect current is allowed to flow in the primary coil, the magneticfield intensity is inevitably increased.

This field intensity may increase until distortion' of the incomingsignal is produced by reason of external materials in the field. Itseffect is to change or suppress the fine variations of the modulatedcurrent, in fact it may entirely eliminate some of the Weakermodulations. As a result of this, the current induced in the secondaryof a transformer in which direct current is allowed to flow in theprimary, does not contain a true reproduction of the modulationsexisting in the radio current originally impressed on the primary.

Since these modulations represent and are produced by the originalvoice, music, etc., and on them, after rectification, depends thereproduction of that voice or music, it is obvious that if they arechanged or suppressed or eliminated to any degree in transit, theresulting reproduction must be untrue and distorted. To meet thiscondition, I have introduced into the plate circuit and preferablybefore the primary a capacity so arranged in one of its functions as toprevent all direct potential from appearing at the primary of thetransformers, but at the same time permitting free flow of the modulatedpulsating radio frequency current into said primaries.

It must be noted that the interposition of such a capacity will resultin a change of phase in the current flowing in the primary of thetransformer. It must be noted that the direction of winding and thepoling of the winding terminals of the primary coil with reference tothe direction of the secondary winding is a factor in maintaining thephase relationship of the component voltages constituting the resultantgrid voltage and the winding direction of the primary is preferablyreversed with respect to the secondary and the poling so chosen as tomaintain the desired characteristics with frequency.

When direct current is allowed to flow in the primary of thetransformers the resulting intensification of the magnetic flux alsogreatly enlarges the external field of the coil. Thus it becomesincreasingly difficult to prevent undesired energy transfer throughinter-stage coupling. If shielding is used the shields for each stagemust be made so large as to be unpracticable, otherwise the entireefliciency of the amplifier is greatly reduced as a result of the largeeddy currents set up. By eliminating all direct current from thetransformers, as I have done in my invention, the external field is soreduced that small close shields may be used and all inter-stagecoupling removed. In fact the external field is so small that in manyinstances shielding may be dispensed with.

I have also found that the voltage drop across the high impedance of thecommon source of plate current supply created by the passage of thepulsating current flowing back from the plate may effect a couplingbetween stages or a feed back to the grid circuit. I have placed chokecoils of such values and in such a position with respect to the powersource and the plate circuit of each stage so as to substantiallyeliminate this very detrimental effect.

The drawing forming part of this specification illustrates in diagramthe circuits embodying my invention. The drawing shows two stages ofradio frequency amplification although the invention is not restrictedto that number. Starting with the antenna circuit, each stage consistspreferably of an air core radio frequency transformer having a minimumof dielectric, of which I is the primary and 2 is the secondary. Thistransformer is tuned by two condensers or other capacities, one ofwhich, 3, is variable, and 4 is fixed; the condenser 4 being in seriesconnection electrically with the condenser 3, and bothbeing in shuntconnection across the ter- Bit minals of the secondary coil 2, thusmaking the combination of capacities 3 and 4 variable when 3 is varied.The circuit also contains an electronic tube-having grid 5, plate 6 andfilament I.

The filament 1 is connected to its battery in the usual manner, and hasin its circuit a suitable resistance 8, preferably in the negative side,to maintain the proper operating condition. The grid 5 is connected toone end of the secondary coil,2; the other end of the secondaryconstituting the grid return being connected into the negative side of thefilament circuit at a point between the resistance 8 and the battery.-

The plate 6 is connected to its battery through a radio frequency chokecoil 9, and to the primary I of the next following radio frequencytransformer through a condenser I0.

In this way, while the direct potential of the plate battery may passreadily to the plate 6 through the choke 9, it can never appear at theprimary I of the radio frequency transformer because of theinterposition of the condenser I0 and the tuning condensers. On theother hand, the electromagnetic component on. the plate being of amodulated pulsating nature will flow readily into the primary coil Ithrough the condenser Ill where it is desired, but is effectivelychecked to an appreciable degree by inherent impedance from flowingfurther into the plate battery circuit or through it into adjacentstages of amplification, where it is not desired, by the interpositionof the choke 9. The primary coil I has its one end connected to theplate of the preceding tube through the condenser Ill, or to the antennain the case of the first stage, and its other end connected to thecommon connector between the rotor plates of the variable condenser 3and one side of the fixed condenser 4.

Thus the variations in the electromagnetic side (the coils I, 2) due tochange of frequency combined with other factors are compensated for inthe electrostatic side which is made up of the condensers 3 and 4, sincethere exists between the primary I and the secondary 2 not only magneticcoupling but also static coupling through the condenser 4 which isitself in series with the condenser 3, the effective values of theseries combination of 3 and 4 being variable. The values andrelationships of all inductances and capacities comprising the entireamplifier circult are such that their variation with changes 01frequency and by the operation of tuning produces a condition ofsubstantial equality between the total inductive reactance and the totalcapacitive reactance at every frequency to which the system may betuned.

It has been pointed out previously in this specification that thedesired condition of true non-regeneration is brought about by theselec- V tion of values of inductances and capacities and theirrelationship which in themselves constitute the amplifier circuit. Thusit is clear that the results obtained with my circuit are obtained bythe co-related effect of the sum of the values of all circuit elementsand their relationships so as to produce zero difference of potentialwith respect to all regenerative currents in any phase. Therefore it isobvious that numerous combinations of such values and relationships,result ing in zero difference of potential with respect to allregenerative currents in any phase, can be obtained for different bandsof frequencies and when distinct characteristics with frequency arerequired. It is impracticable to set forth in this specification all thepossible combinations of values to maintain zero difference of potentialwith respect to regenerative currents in. any phase for all frequencybands. Therefore, I have set forth a plane of reference, namely,-zer0difference of potential with respect to all regenerative currents in anyphase, as common to all combinations of values and relationships and asexpressing the measure of the requirements of my system at anyfrequency. A usual method of selecting the tentative effective values ofinductances and capacities, both self and mutual, as described by me inmy specificationszandl drawing, applicable to the present day broadcastband of 550-l500'kilocycles, would be as follows,first consider theselective circuit which is shown in my drawing as inductance 2 shuntedby capacities 3 and 4. of a standard type adapted to tune the broadcastband. It must be noted that the actual tuning capacity as associatedwith inductance 2 is composed of condensers 3 and 4 in series and oneskilled in the art would know that the net tuning capacity would be oneover the sum of the reciprocals of the two capacity values which wouldresult in a maximum tuning capacity somewhat less than the actual value01. the variable condenser. I have stated in my specifications that theratio of the value between condenser 4 and condenser 3 is approximately20-1. According to recognized trade practice this ratio will beunderstood to refer tothe maximum value of the variable condensers.Having determined the net tuning value of condensers 3 and 4 theinductance 2 must be chosen of such a value as to tune the required bandof frequencies. With these facts one skilled in the art can readilydetermine the value of these three impedances. Turn now to the primaryinductance I and the mutual between I and 2. These values would beselected by a designer in accordance to his desires as to sensitivityand selectivity following the well known principles covering theserequirements. Ordinarily it has been found that for satisfactorysensitivity and selectivity in the broadcast band the inductance largeas the inductance of primary I. Having selected a value for theinductance I and determined the adjustment of its couplingwithinductance 2, there are measurement methods or formulas to determinethe values of the mutual inductance between I and 2. The reactancevalues of these impedances can easily be obtained by applying well knownformulas. Condenser IO must be capable of withstanding the dynamic peakpotential at the plate and have a high value of leakage resistance andis chosen of such capacity that the resultant algebraic sum of thereactance of the inductive elements I, 2 and the mutual therebetween andthe capacitive elements 3; 4 and Ill is zero, and since these elementsconstitute all the reactance elements within the output circuit, thatcircuit becomes non-reactive, having a total impedance consisting merelyof its residual resistance and therefore there can be no generation ofcurrents in either phase across the elements of its associatedelectronic device. The coupling between coil I and coil 2 adjusted withcondenser 4 and condenser I 0 in conjunction with other circuit valuesis such as to simultaneously maintain the desired characteristics withfrequency and non-regeneration. The direction of winding of coil 'I withreference to coil 2 is reversed and. the poling chosen so that theresultant voltage The variable condenser 3 may be 45- of the secondary 2will be at least ten times as I former, said capacity being also inseries with appearing at the grid of the next tube is composed ofvoltages in such phase as to obtain the desired characteristics.

What I claim is:

l. A system of amplification of radiant energy with no production ofregenerative currents to either aid or oppose the desired amplificationand without external circuit elements to divert or dissipate usefulsignal energy for the suppression or control of regeneration, whereinonly the useful and desired currents are permitted and are restricted totheir proper and useful paths; comprising input means for an electronicdevice and one or more stages of amplification, each stage comprising incombination an electronic device, self and mutual inductive impedanceelements including a transformer, and self and mutual capacitiveimpedance elements, wherein the plate of each preceding electronicdevice is connected to the primary of the following transformer througha connection consisting of a self capacitive impedance element; andwherein thecondition of complete non-regeneration simultanously withconstant and maximum response with fidelity of the signal is obtained atthe output of the system for a constant input at all frequencies towhich the system is tunable and the system is applicable to any desiredband of frequencies and to any desired sensitivity or selectivity; thiscondition being obtained by the combination of the capacitive andinductive impedance elements, both self and mutual, in coordination andoperating as a unitary system and by the selection of the magnitudes andvalues of said impedances and impedance elements, and the electricalrelation and circuit position of each impedance to the others, so thatwhen the system is tuned at any frequency to which the system is tunablethe sum of all the capacitive reactances, both self and mutual, and thesum of all the inductive reactances, both self and mutual, issubstantially zero; to obtain a zero difference of potential in respectto all regenerative currents in any phase across the interelectrodecapacities of the electronic device.

2. A system of amplification of radiant energy comprising in combinationan electronic device, the input of which consists of a transformer, avariable capacity, a capacity connected in series between the primaryand secondary of the trans the variable capacity and said seriescapacity combination being connected in shunt across the secondary ofthe transformer; an output circuit comprising in combination atransformer, a capacitive self-impedance connected in series with theplate of the electronic device and the following primary of saidtransformer, av variable capacity, a capacity connected in seriesbetween the primary and secondary of the transformer, the seriescapacity combination being connected in shunt across the secondary ofthe transformer, said secondary providing output terminals for thesystem; the electrical values, both self and mutual, of theaforementioned inductances'and capacities constituting the outputcircuit being of such impedance magnitudes and so related to produce azero difference of potential in respect to all regenerative currents inany phase between the elements of the electronic device and constitutinga system which is non-regenerative; and the plate of the electronicdevice being connected to a source of direct current through animpedance placed in series between the plate and the source of directcurrent for the purpose or preventing the flow of alternating currentback through the sourceof direct current supply, but allowing the freeflow of the modulated alternating currents from the plate through theprimary of the transformer.

3. A system of amplification of radiant energy comprising in combinationan electronic device, 5, 6 and 1, the input of which consists of atransformer, I and 2, a variable capacity, 3, a capacity, 4, connectedin series between the primary and secondary of the transformer, saidcapacity being also in series with the variable capacity and said seriescapacity combination, 3 and 4, being con nected in shunt across thesecondary of the transformer; an output circuit comprising incombination a capacitive self-impedance, l0, connected in series betweenthe plate, 6, of the electronic device and the following primary, I, atransformer, I and 2, a variable capacity, 3, a capacity, 4, connectedin series between the primary and secondary of the transformer, theseries capacity combination being connected in shunt across thesecondary of the transformer, combined with one or more successivestages of amplification, each stage comprising in combination anelectronic device whose grid input is connected across the terminals ofthe secondary, 2, and whose output circuit is comprised of the elementsof the output circuit above mentioned; the electrical values, both selfand mutual, of the inductances and capacities constituting each outputcircuit being of such impedance magnitude and so related to produce zerodifference of potential in respect to all regenerative currents in anyphase between the elements of the electronic device and constituting asystem which is non-regenerative; and each plate, 5, of the electronicdevices being connected to a source of direct current through animpedance, 9, placed in series between each plate and the source ofdirect current for the purpose of preventing the flow of alternatingcurrent back through the source of direct current supply, but allowingthe free flow of the modulated alternating currents from the platesthrough the primaries of the transformers.

4. A system of amplification of radiant energy comprising in combinationa first and a following electronic device, said first electronic devicehaving input means, and an output circuit consisting of a transformer, avariable capacity, a capacity connected in series between the primaryand secondary of the transformer, said capacity being also in serieswith the variable capacity, and both capacities being connected in shuntacross the secondary of the transformer, the high potential end of saidsecondary being connected to the grid of the following electronic deviceand the low potential end of the secondary being connected to ground orthe filament of the following electronic device or some common terminal;and another capacity connected in series between the plate of they firstelectronic device and the primary, and the electrical values, both selfand mutual, of the said inductances and said capacities being relativelysuch that the system is non-regenerative.

5. A system of amplification of radiant energy comprising in combinationan electronic device, having input means, and an output circuitconsisting of a transformer, a variable capacity, a capacity connectedin series between the primary and secondary of the transformer, saidcapacity being also in series with the variable capacity, and bothcapacities being connected in shunt across the secondary of thetransformer, and furthermore a capacity connected in series between theplate of the electronic device and the primary, and the electricalvalues, both self and mutual, of the said inductances and of the saidcapacities being relatively such that the system is nonregenerative.

6. A system of amplification of radiant energy consisting of elements asset forth in claim 5, the output circuit elements of which providecapacities to form an electrostatic path of energy trans fer whose valueis definitely variable, and inductances comprising a transformer to forman electromagnetic path whose value is naturally variable with changesof frequency; the electrical relationship of these two paths and theirimpedance values, associated with the self-impedance values, being suchthat a maximum transfer of energy is obtained without regeneration orany flow of regenerative currents in any phase at every desiredfrequency.

7. A system of amplification of radiant energy consisting of elements asset forth in claim 5 wherein the capacity connected between the plate ofthe electronic device and the primary, as set forth in claim 5, has forone of its purposes, in conjunction with its associated capacities, theprevention of the appearance of direct potential at the primary of thetransformer, but permitting the free flow of the modulated alternatingcurrents from the plate through the primary of the transformer and saidplate being connected to its source of direct current through a highfrequency impedance placed in series between the plate and the source ofdirect current for the purpose of minimizing the flow of alternatingcurrent back through the source of direct current supply, but permittingthe flow of direct current from its source to the plate.

8. A system of amplification of radiant energy consisting of elements asset forth in claim 5, combined with one or more additional stages, eachstage having a capacity of suitable value connected between the plate ofthe electronic device and the following primary as set forth in claim 5,and having a suitable source of direct current connected in shunt to apoint in the circuit between said plate and the above mentionedcapacity, and having a high frequency impedance of suitable valueinterposed in series in the above mentioned shunt between the source ofdirect current and the plate, for the purpose of separating the currenton the plate into two components, one of which is a modulatedalternating component which is allowed to pass freely into thetransformer of such stage, but is highly impeded in its flow backthrough the common source of direct current supply, the other componentbeing a direct current component which is allowed to pass freely fromthe direct current source to the plate, but is not allowed to appear atthe primary of the transformer of such stage.

9. A system of amplification of radiant energy consisting of elements asset forth in claim 5 the output circuit of which comprises anelectromagnetic mutual path and an electrostatic mutual path of energytransfer, the impedance values of which are variable automatically bythe act of tuning, said values being so related to each other and to theself-impedance values of the system as to produce a zero difference ofpotential in respect to all regenerative currents in any phase betweenthe grid and plate of the electronic device when the amplifier is tunedto any given frequency.

10. A system of amplification of'radiant energy comprising an electronicdevice, the input of which consists of a transformer, a variablecapacity, a capacity connected in series between the primary andsecondary of the transformer, said capacity being also in series withthe variable capacity, and said series capacity combination beingconnected in shunt across the secondary of the transformer, and anoutput circuit consisting of a transformer, a variable capacity,'acapacity connected in series between the primary and secondary of saidtransformer, said capacity being also in series with the variablecapacity and both capacities being connected in shunt across thesecondary of the transformer and furthermore a capacity connected inseries between the plate of the electronic device and the primary, andthe impedance values, both self and mutual, of said inductances andcapacities being so selected and so related to each other as tosimultaneously maintain a condition of complete nonregeneration and acondition of energy transfer maintained constant .at its maximum valueat every desired frequency.

11. A system of amplification of radiant energy 1 comprising anelectronic device the input of which consists of a transformer, avariable capacity, a capacity connected in series between the primaryand secondary of the transformer, said capacity being also in serieswith the variable capacity, and said series capacity combination beingconnected in shunt across the secondary of the transformer, and anoutput circuit consisting of a transformer, a variable condenser and aseries condenser, said variable and series condensers being connected inseries with each other and the two being connected in shunt across thesecondary of said transformer and one end of the primary of saidtransformer being connected into the series connection between the twosaid condensers, the other end of the primary connected through acondenser to the preceding plate and the impedance values, both self andmutual, of said primary and secondary and of said condensers beingselected so as to prevent the production of undesired disturbingoscillations in the circuits associated with the electronic device atall frequencies to which the system is tunable.

12. In a system of amplification of radiant energy comprising anelectronic device, the input of which consists of a transformer, avariable capacity, a capacity connected in series between the primaryand secondary of the transformer, said capacity being also in serieswith the variable capacity, and said series capacity combination beingconnected in shunt across the secondary of the transformer, and anoutput circuit consisting of a transformer, a variable capacity, acapacity connected in series between the primary and secondary of saidtransformer, said capacity being also in series with the variablecapacity and both capacities being connected in shunt across thesecondary of the transformer and furthermore a capacity connected inseries between the plate and the following primary, the process ofselecting the magnitudes and values of said inductances and capacities,both self and mutual, in combination, and their electrical and circuitrelation to each other to maintain the total inductive reactance of theoutput circuit substantially equal to its total capacitive reactance atall frequencies to which the system is tunable; wherein a zerodifference of potential in respect to all regenerative currents in anyphase across the interelectrode capacities of the tube or otherelectronic device is obtained, simultaneously maintaining completenon-regeneration and energy transfer over the entire system constant atits maximum value.

13. In a system of amplification of radiant energy comprising anelectronic device, the input of which consists of a transformer, avariable capacity, a capacity connected in series between the primaryand secondary of the transformer, said capacity being also in serieswith the variable capacity, and said series capacity combination beingconnected in shunt across the secondary of the transformer, and anoutput circuit consisting of a transformer, a variable capacity, acapacity connected in series between the primary and secondary of saidtransformer, said capacity being also in series with the variablecapacity; and both capacities being connected in shunt across thesecondary of the transformer and furthermore a capacity connected inseries between the plate and the following primary, said capacitiesproviding electrostatic paths, both self and mutual, and saidinductances providing electromagnetic paths, both self and mutual, theprocess consisting in the selection of the magnitudes and values and theelectrical and circuit relation of the said inductances and capacities,both self and mutual, in combination, to obtain an equality between thetotal capacitive reactance and the total inductance reactance, and inautomatically varying the total reactance of the electrostatic elementsas the variable capacity is varied to such a degree as to compensate forthe natural change in total reactance of the electromagnetic elementsarising from change of frequency, to obtain a condition of completenon-regeneration and simultaneously a condition of energy transfermaintained constant at its maximum value for any desired frequency towhich the system is tunable.

'14. In a system of amplification of radiant energy comprising anelectronic device having input means and an output circuit consisting ofa transformer, a variable capacity, a capacity connected in seriesbetween the primary and secondary of said transformer, said capacitybeing alsoin series with the variable capacity, and both capacitiesbeing connected in shunt across the secondary of the transformer andfurthermore a capacity connected in series between the plate and thefollowing primary, said capacities providing static paths, both self andmutual, and said inductances providing magnetic paths, both self andmutual, the process consisting in the selection of the magnitudes andvalues and the electrical and circuit relation of the said inductancesand capacities, both self and mutual, in combination, to obtain anequality between the total capacitive reactance and the total inductivereactance, and in automatically varying the total reactance of theelectrostatic elements as, the variable capacity is varied to such adegree as to compensate for the natural change in total reactance of theelectromagnetic elements arising from change of frequency, to obtain acondition of complete non-regeneration and simultaneously a condition ofenergy transfer maintained constant at its maximum value for any desiredfrequency to which'the system is tunable.

15. A system of amplification of radiant energy consisting of elementsas set forth in claim 5, combined with one or more additional stages ofamplification, the plate of each electronic device being connected toits source of direct current through a high frequency impedance betweensaid plate and said source of direct current for the purpose ofpresenting a high impedance to the flow of high frequency currentthrough the direct current supply, but readily permitting the fiow ofdirect current from its source to the said plate, each plate beingconnected to the primary of the following transformer through a capacityas set forth in claim 5, one purpose of which in conjunction with itsassociated capacities is to prevent the appearance of direct potentialin the primary of the transformer, said capacity further being chosenand in such relationship with reference to all the other capacities andinductances, both self and mutual, in the system as setforth in claim 5as to maintain a substantial equality between the sum of the inductivereactances and the sum of the capacitivereactanc'es at any frequency towhich the system is tuned, resulting in a zero difference of potentialwith respect to all regenerative currents in any phase between grid andplate of the electronic device thereby simultaneously maintaining acondition of optimum and constant energy transfer with no regeneration.

JOSEPH J. DALEY.

